Re: [dpdk-dev] [PATCH v4 0/3] vhost: make virtqueue cache-friendly

On Tue, 2021-03-23 at 11:30 +0100, David Marchand wrote:

On Tue, Mar 23, 2021 at 10:02 AM Maxime Coquelin
[off-list ref] wrote:

quoted

As done for Virtio PMD, this series improves cache utilization
of the vhost_virtqueue struct by removing unused field,
make the live-migration cache dynamically allocated at
live-migration setup time and by moving fields
around so that hot fields are on the first cachelines.

With this series, The struct vhost_virtqueue size goes
from 832B (13 cachelines) down to 320B (5 cachelines).

With this series and the virtio one, I measure a gain
of up to 8% in IO loop micro-benchmark with packed
ring, and 5% with split ring.

I don't have a setup at hand to run PVP testing, but
it might be interresting to get the numbers as I
suspect the cache pressure is higher in this test as
in real use-cases.

Changes in v4:
==============
- Fix missing changes to boolean (Chenbo)

For the series,
Reviewed-by: David Marchand <redacted>

Merci !

Tested this in a PVP setup on ARM, giving a slight improvement in
performance. For the series:

Tested-by: Balazs Nemeth <redacted>